| 摘要 |
PROBLEM TO BE SOLVED: To securely discriminate an oblique flaw in a signal from a similar image structure by integrating pixels which are arranged in array and forming a group, and classifying flaw section and no-flaw section according to a specific criterion. SOLUTION: The output signal of a pulse band-pass filter 110 which filters pulsating image variation is supplied to a flaw section detector 120. In the detector 120, a quantizer 121 has two switching thresholds and indicates a black flaw below the negative threshold value -C and a white flaw above the threshold value +C. Then a scanning line accumulator 122 for a specific number of scanning lines generate the sum of the output value of the quantizer 121 individually according to a horizontal position and its output value is supplied to discriminators 123 and 124 to detect partial sections of a white flaw and a black flaw. Consequently, pixels of a flaw which vary a vertical position on a selected scanning line by up to the pulse bandwidth of the filter 110 can nearly be acquired. |
